Time-Sensitive Switch for Scheduled Data Egress

ABSTRACT

Systems and methods for scheduling data egress using a time-sensitive (TS) network switch. The TS network switch may include a functional unit, a plurality of ports, and a plurality of queues. Each port may be associated with a set of network addresses for TS packets and may be configured with a set of egress periods. Each queue may be associated with a TS packet type and a port. The functional unit may be configured to receive TS packets asynchronously from a network node via a first port, determine a second port for egressing a TS packet, determine an egress period for egressing the TS packet, determine that the TS packet cannot currently be egressed from the second port, queue the TS packet in a first queue, where the first queue is associated with the second port, and egress the TS packet in the respective time window from the second port.

FIELD OF THE INVENTION

The present invention relates to the field of time-sensitive (TS)networks, and more particularly to systems and methods forinteroperability between networks, including managing the configurationof virtual local area network (VLAN) tags and data flow paths between aTS network and a non TS (NTS) network, synchronization of clocks betweennetworks, and scheduling data egress.

DESCRIPTION OF THE RELATED ART

In the industrial or embedded application field there are multiplereal-rime Ethernet implementations that are available. Although similarin function, each implementation differs such that each implementationis not interoperable with another implementation. For example, PROFINET,Ethernet for Control Automation Technology (EtherCAT), EthernetIndustrial Protocol (Ethernet/IP), and Ethernet Powerlink use the sameEthernet physical layer but are not interoperable amongst themselves.Additionally, these real-time Ethernet implementations cannot connect tostandard IEEE 802.1 switches because the implementation of the mediaaccess control (MAC) layer used by each is customized to support its ownproprietary protocol. Thus, since there is a multitude of existingdeployments of real-time Ethernet based protocols, hereinafter referredto as non-time-sensitive (NTS) networks, there is a need to define howthese existing proprietary technologies can coexist with standard IEEE802.1 Ethernet technologies.

For example, the features that add real time data transfer support tostandard Ethernet under IEEE 802.1 are collectively called TimeSensitive (TS) Networking. These features define stream reservation andtime based scheduling in IEEE 802.1 in Ethernet switches. One the onehand, stream reservation guarantees bandwidth toreal-time/time-sensitive streams, e.g., packets, end to end. On theother hand, time-based scheduling allows configuration of “windows oftime” when only specific packets are allowed to egress a switch.“Windows of time” may be coordinated with transmission of time-sensitivepackets, or TS packets, by endpoints to minimize the age of a datastream as it passes through the network. “Windows of time” also boundsthe maximum latency of the stream from the producer to the consumerssuch that a precise schedule may be determined.

TS networking is based on Virtual Local Area Network (VLAN). A VLAN is adistinct isolated broadcast domain. VLANs are partitioned out of localarea networks (LANs) and can only pass data between each other via arouter or routers. Additionally, VLAN allows a switched network to belogically segmented on an organizational basis. In other words, thenetwork is segmented by functions or applications rather than on aphysical or geographical basis. A TS network predefines specific VLANtags which allow identification of a TS packet as it is routed through aLAN.

A TS network interface controller (NIC) supports TS networking featuresvia multiple queues. The queues segregate LAN traffic based on VLANtags. However, as mentioned, non-time-sensitive, or NTS, network devicestypically implement a custom MAC which is not IEEE 802.1 compliant, andthus, not compatible with TS networks. Therefore, there is a need for asolution to allow interoperability between TS networks and NTS networks,including the need to synchronize clocks between networks and the needto schedule data egress.

SUMMARY OF THE INVENTION

Various embodiments of a system and method for interoperability betweennetworks, including managing the configuration of virtual local areanetwork (VLAN) tags and data flow paths between a TS network and a nonTS (NTS) network, synchronization of clocks between networks, andscheduling data egress are presented below.

In one embodiment, a system for interoperating between a time-sensitive(TS) network and a non-time-sensitive (NTS) network may include a TSnetwork switch and a TS network interface controller (NIC). The TSnetwork switch may include a first functional unit coupled to aplurality of ports. In certain embodiments, a first port of theplurality of ports may be configured to couple to an NTS node of the NTSnetwork. The TS NIC may include a second functional unit, a third port,a plurality of NTS receive packet queues, and a corresponding pluralityof NTS transmit packet queues. Further, the TS NIC may be configured tocouple to a second port of the plurality of ports of the TS networkswitch. In some embodiments, the third port may be coupled to the secondfunctional unit. Additionally, the plurality of NTS receive packetqueues may be coupled to the second functional unit and the third portand may be configured to store received packets from respective NTSnetworks. The corresponding plurality of NTS transmit packet queues maybe coupled to the second functional unit and the third port and may beconfigured to store packets received from a device coupled to the TS NICfor the respective NTS networks. A first NTS receive packet queue (ofthe plurality of NTS receive packet queues) and a first NTS transmitpacket queue (of the plurality of NTS transmit packet queues) may eachcorrespond to the NTS network.

In an exemplary embodiment, the first functional unit may be configuredto insert a virtual local area network (VLAN) tag indicating the NTSnetwork into each NTS packet received from the NTS network by the firstport before routing each NTS packet to one or more other ports of theplurality of ports in the TS network switch, thereby generating taggedNTS packets. In addition, the first functional unit may be configured toremove the VLAN tag from each received VLAN tagged NTS packet beforeforwarding, via the first port, each received VLAN tagged NTS packet tothe NTS node. Also, the first functional unit may be configured toreceive, via the second port, one or more of the tagged NTS packets fromthe first port and forward, via the second port, the one or more taggedNTS packets to the TS NIC and receive, via the second port, tagged NTSpackets from the TS NIC and route tagged NTS packets to the first port.

Additionally, in such embodiments, the second functional unit may beconfigured to queue tagged NTS packets received via the third port inthe first NTS receive packet queue for subsequent provision to thedevice coupled to the TS NIC and queue NTS packets received from thedevice coupled to the TS NIC in the first NTS transmit packet queue andinsert the VLAN tag indicating the NTS network into each NTS packetreceived from the first NTS transmit packet queue before forwarding, viathe third port, each NTS packet to the second port, thereby generatingtagged NTS packets.

In further embodiments, a TS network node may include the TS NIC. Inother embodiments, the TS network node may include the TS network switchand the TS NIC and may be configured as a bridge between the TS networkand the NTS network. In such embodiments, the system may further includeone or more additional TS network nodes. Each TS network node of the oneor more additional TS network nodes may include a respective TS networkswitch and TS NIC. Thus, a plurality of TS network nodes may include theTS network node and the one or more additional TS network nodes.Accordingly, in certain embodiments, each TS network node of theplurality of TS network nodes may be configured as a bridge between theTS network and a respective NTS network, thereby allowinginteroperability between the TS network and a plurality of NTS networks.

In some embodiments, another one or more other ports of the plurality ofports of the TS network switch may each be configured to couple to acorresponding other NTS network via a respective NTS node of thecorresponding other NTS network. In such other further embodiments, thefirst functional unit may be further configured to insert a VLAN taginto each NTS packet received by each of the another one or more otherports from the NTS node of the corresponding other NTS network beforerouting each NTS packet to one or more ports of the plurality of portsin the TS network switch, where the VLAN tag indicates the respectiveNTS network, thereby generating tagged NTS packets, and remove the VLANtag from received VLAN tagged NTS packets before forwarding, via each ofthe another one or more other ports, each of the received VLAN taggedNTS packets to the respective NTS node of the corresponding other NTSnetwork.

In accordance with the above, a method for interoperating between a TSnetwork and an NTS network may include configuring a TS network switchand a TS NIC. The TS network switch may include a plurality of ports anda first functional unit coupled to the plurality of ports. Configuringthe TS network switch may include configuring a first port of theplurality of ports to couple to an NTS node of the NTS network andconfiguring a second port of the plurality of ports to couple to a TSnetwork interface controller (NIC).

In some embodiments, configuring the TS network switch may includeconfiguring the first functional unit. Accordingly, the first functionalunit may be configured to insert a VLAN tag indicating the NTS networkinto each NTS packet received from the NTS network by the first portbefore routing each NTS packet to one or more other ports of theplurality of ports in the TS network switch, thereby generating taggedNTS packets and remove the VLAN tag from each received VLAN tagged NTSpacket before forwarding, via the first port, each received VLAN taggedNTS packet to the NTS node. Further, the first functional unit may beconfigured to receive one or more of the tagged NTS packets from thefirst port and forward, via the second port, the one or more tagged NTSpackets to the TS NIC and receive, by the second port, tagged NTSpackets from the TS NIC and route tagged NTS packets to the first port.

As noted above, TS NIC may include a second functional unit, a thirdport, coupled to the second functional unit, a plurality of NTS receivepacket queues, coupled to the second functional unit and the third port,and a corresponding plurality of NTS transmit packet queues, coupled tothe second functional unit and the third port. Accordingly, configuringthe TS NIC may include configuring the second functional unit. In suchembodiments, the second functional unit may be configured to queuetagged NTS packets received via the third port in the first NTS receivepacket queue for subsequent provision to the device coupled to the TSNIC and queue NTS packets received from the device coupled to the TS NICin the first NTS transmit packet queue and insert the VLAN tagindicating the NTS network into each NTS packet received from the firstNTS transmit packet queue before forwarding, via the third port, eachNTS packet to the second port, thereby generating tagged NTS packets.

In certain embodiments, the first functional unit may insert the VLANtag indicating the NTS network into each NTS packet received by thefirst port from the NTS network before routing each NTS packet to one ormore other ports of the plurality of ports in the TS network switch,thereby generating tagged NTS packets and removing the VLAN tag fromeach received VLAN tagged NTS packet by the first port before forwardingeach received VLAN tagged NTS packet to the NTS node. Additionally, oneor more of the tagged NTS packets may be received from the first portand forwarded, via the second port to the TS NIC. Similarly, tagged NTSpackets from the TS NIC may be received by the first functional unit viathe second port and routed to the first port.

In addition, the second functional may queue tagged NTS packets receivedvia the third port in the first NTS receive packet queue for subsequentprovision to the device coupled to the TS NIC. Additionally, NTS packetsreceived from the device coupled to the TS NIC in the first NTS transmitpacket queue may be queued. Accordingly, the VLAN tag indicating the NTSnetwork may be inserted into each NTS packet received from the first NTStransmit packet queue before forwarding, via the third port, each NTSpacket to the second port, thereby generating tagged NTS packets.

In other embodiments, the method may further include configuring each ofanother one or more other ports of the plurality of ports of the TSnetwork switch to couple to a corresponding other NTS network via arespective NTS node of the corresponding other NTS network. In suchother embodiments, the first functional unit may be further configuredto insert a VLAN tag into each NTS packet received via each of theanother one or more other ports from the NTS node of the correspondingother NTS network before routing each NTS packet to one or more ports ofthe plurality of ports in the TS network switch, where the VLAN tagindicates the respective NTS network, thereby generating tagged NTSpackets and remove the VLAN tag from received VLAN tagged NTS packetsbefore forwarding, via each of the another one or more other ports, eachof the received VLAN tagged NTS packets to the respective NTS node ofthe corresponding other NTS network. Additionally, such an embodimentmay further include coupling each of the another one or more other portsto the corresponding other NTS network via the respective NTS node ofthe corresponding other NTS network.

Further, the first functional unit may insert a VLAN tag into each NTSpacket received via each of the another one or more other ports from theNTS node of the corresponding other NTS network before routing each NTSpacket to one or more ports of the plurality of ports in the TS networkswitch, where the VLAN tag indicates the respective NTS network, therebygenerating tagged NTS packets. Similarly, the VLAN tag from receivedVLAN tagged NTS packets may be moved before being forwarded, via each ofthe another one or more other ports, to the respective NTS node of thecorresponding other NTS network.

In an exemplary embodiment, a TS network node for interoperating betweena TS network and an NTS network may include a functional unit, aplurality of ports which may be coupled to the functional unit, aplurality of NTS receive packet queues which also may be coupled to thefunctional unit, and a corresponding plurality of NTS transmit packetqueues which also may be coupled to the functional unit. Additionally, afirst port of the plurality of ports may be configured to couple to anNTS node of the NTS network. Further, the plurality of NTS receivepacket queues may be configured to store received packets fromrespective NTS networks and a first NTS receive packet queue maycorrespond to the NTS network. Similarly, the corresponding plurality ofNTS transmit packet queues may be configured to store packets receivedfrom a device coupled to the TS NIC for the respective NTS networks anda first NTS transmit packet queue may correspond to the NTS network.Also, the functional unit may be configured to communicate tagged NTSpackets with the TS network via a second port and insert a VLAN tagindicating the NTS network into each NTS packet received from the NTSnetwork by the first port before routing each NTS packet to the secondport, one or more other ports of the plurality of ports, or to the firstNTS receive packet queue, thereby generating tagged NTS packets. Thefunctional unit may also be configured to remove the VLAN tag from eachVLAN tagged NTS packet received by the second port, the one or moreother ports of the plurality of ports, or from the first NTS transmitpacket queue before forwarding, via the first port, each received VLANtagged NTS packet to the NTS node of the NTS network. In addition, thefunctional unit may be configured to queue at least a subset of taggedNTS packets received by the TS network node in the first NTS receivepacket queue for subsequent provision to the device coupled to the TSnetwork node and queue NTS packets received from the device coupled tothe TS network node in the first NTS transmit packet queue and insertthe VLAN tag indicating the NTS network into each NTS packet queued inthe first NTS transmit packet queue before forwarding each NTS packet tothe first port, thereby generating tagged NTS packets.

In one embodiment, a TS NIC may be configured to synchronize an NTSnetwork timekeeper. In such embodiments, the TS NIC may include afunctional unit, a port coupled to the functional unit, a clock, coupledto the functional unit and synchronized to a master clock, a pluralityof input/output queue pairs, coupled to the functional unit and theport, and a time stamp unit (TSU) coupled to the clock and thefunctional unit. The plurality of input/output queue pairs may be forsegregation of VLAN packets based on VLAN tags, wherein eachinput/output queue pair may correspond to a respective NTS network. Insuch an embodiment, the functional unit may be configured to, for eachof the respective NTS networks, generate synchronization packets usableby an NTS network timekeeper of the respective NTS network tosynchronize the NTS network to the master clock. In certain embodiments,generating synchronization packets may include using the TSU to generatetime stamps for the synchronization packets in accordance with the clocksynchronized to the master clock. Additionally, the functional unit maybe configured to communicate with the respective NTS network via theport using the corresponding input/output queue pair, including sendingthe synchronization packets to the NTS network timekeeper of therespective NTS network. In certain embodiments, the functional unit mayalso be configured to egress the synchronization packets via the outputqueue of the at least one input/output queue pair based on a specifiedegress period, wherein the specified egress period specifies a timewindow and frequency for egressing the synchronization packets.

In some embodiments, the TS NIC may be included in a TS network node.Additionally, in certain embodiments, the TS network node may furtherinclude a TS network switch.

In another embodiment, the master clock may be a master clock of a TSnetwork. In such embodiments, the master clock may be included in a TSnetwork switch. In other embodiments, the master clock may be externalto the TS network. In certain embodiments, the master clock may be anNTS network timekeeper. In some embodiments, the master clock may besynchronized to a global clock external to the TS network.

In yet another embodiment, the TSU may be included in the physical layerof the TS NIC.

In an exemplary embodiment, a method for the TS NIC to synchronize anNTS network timekeeper may include configuring the clock of the TS NICto synchronize to the master clock. Additionally, the functional unitmay be configured to, for each of the respective NTS networks, generatesynchronization packets usable by an NTS network timekeeper of therespective NTS network to synchronize the NTS network to the masterclock. In some embodiments, generating synchronization packets mayinclude using a TSU to generate time stamps for the synchronizationpackets in accordance with the clock synchronized to the master clock.The functional unit may also be configured to communicate with therespective NTS network via the port using the corresponding input/outputqueue pair, including sending the synchronization packets to the NTSnetwork timekeeper of the respective NTS network. Additionally, incertain embodiments, the functional unit may be configured to egress thesynchronization packets via the output queue of the at least oneinput/output queue pair based on a specified egress period, wherein thespecified egress period specifies a time window and frequency foregressing the synchronization packets.

In some embodiments of the method, the functional unit may generatesynchronization packets usable by an NTS network timekeeper of therespective NTS network to synchronize the NTS network to the masterclock, including using the TSU to generate time stamps for thesynchronization packets in accordance with the clock synchronized to themaster clock and communicate with the respective NTS network via theport using the corresponding input/output queue pair, including sendingthe synchronization packets to the NTS network timekeeper of therespective NTS network. Additionally, the synchronization packets may beegresses via the output queue of the at least one input/output queuepair based on a specified egress period, where the specified egressperiod specifies a time window and frequency for egressing thesynchronization packets.

In another exemplary embodiment, a TS network switch for scheduled dataegress may include a functional unit, a plurality of ports which may becoupled to the functional unit, and a plurality of queues which may becoupled to the plurality of ports and the functional unit. Each port maybe associated with a respective set of network addresses for TS packetsand may be configured with a respective set of egress periods. Each TSpacket may have a destination address and a type that specifies arespective egress period, wherein each egress period specifies arespective time window and frequency for egressing TS packets to networknodes based on the type of the TS packets. Additionally, each queue maybe associated with a respective TS packet type and a respective port ofthe plurality of ports.

In such an embodiment, the functional unit may be configured to receiveone or more TS packets asynchronously from a network node via a firstport and determine a second port of the plurality of ports for egressingat least one of the one or more the TS packets and the determination ofthe second port may be based on the destination address of the at leastone TS packet. Further, the functional unit may be configured todetermine an egress period for egressing the at least one TS packet andthe determination of the egress period may be based on the type of theat least one TS packet. Also, the functional unit may be configured todetermine that the at least one TS packet cannot currently be egressedfrom the second port. In certain embodiments, in order to determine thatthe at least one TS packet cannot currently be egressed from the secondport, the functional unit may also be configured to determine that arespective time window for egress of the at least one TS packet isclosed, determine that there is already a queued TS packet of the sametype queued in the first queue for egress from the second port, ordetermine that the second port is currently egressing a TS packet.

Additionally, in response to determining that the at least one TS packetcannot currently be egressed, the functional unit may be configured toqueue the at least one TS packet in a first queue of the plurality ofqueues based on the respective TS packet type and destination addressand the first queue may be associated with the second port. In addition,the functional unit may egress the at least one TS packet in therespective time window from the second port.

In certain embodiments, the at least one TS packet may include two ormore TS packets and the respective time window of the determined egressperiod may be specified to allow the egress of one of the two or more TSpackets. In other embodiments, the at least one TS packet may includetwo or more TS packets and specifying the respective time window of thedetermined egress may include determining a quantity of the two or moreTS packets to egress each egress period configuring the respective timewindow to allow the egress of the quantity each egress period.

In some embodiments, the first port may be configured to couple to anNTS node of an NTS network and the second port may be configured tocouple to an NTS node of another NTS network.

In other embodiments, the first port may be configured to couple to a TSnetwork node of a TS network and the second port may be configured tocouple to an NTS node of a NTS network.

In one exemplary embodiment, a method for scheduled data egress mayinclude providing the TS network switch which may include a functionalunit, a plurality of ports which may be coupled to the functional unit,and a plurality of queues which may be coupled to the plurality of portsand the functional unit. The functional unit may be configured toreceive one or more TS packets asynchronously from a network node via afirst port and determine a second port of the plurality of ports foregressing at least one of the one or more the TS packets based on thedestination address of the at least one TS packet. Additionally, thefunctional unit may be configured to determine an egress period foregressing the at least one TS packet based on the type of the at leastone TS packet and determine that the at least one TS packet cannotcurrently be egressed from the second port. In certain embodiments,determining that the at least one TS packet cannot currently be egressedfrom the second port may include configuring the functional unit todetermine that a respective time window for egress of the at least oneTS packet is closed, determine that there is already a queued TS packetof the same type queued in the first queue for egress from the secondport, or determine that the second port is currently egressing a TSpacket.

Further, the functional unit may be configured to queue the at least oneTS packet in the first queue of the plurality of queues based on therespective TS packet type and destination address in response todetermining that the at least one TS packet cannot currently be egressedand egress the at least one TS packet in the respective time window fromthe second port.

In some embodiments of the method, the functional unit may receive oneor more TS packets asynchronously from a network node via a first portand determine a second port of the plurality of ports for egressing atleast one of the one or more the TS packets based on the destinationaddress of the at least one TS packet. Additionally, an egress periodfor egressing the at least one TS packet based on the type of the atleast one TS packet may be determined. It may also be determined thatthe at least one TS packet cannot currently be egressed from the secondport. In certain embodiments, determining that the at least one TSpacket cannot currently be egressed from the second port may includedetermining that a respective time window for egress of the at least oneTS packet is closed, determining that there is already a queued TSpacket of the same type queued in the first queue for egress from thesecond port, or determining that the second port is currently egressinga TS packet.

Further, the functional unit may queue the at least one TS packet in afirst queue of the plurality of queues based on the respective TS packettype and destination address in response to determining that the atleast one TS packet cannot currently be egressed. Accordingly, the atleast one TS packet may be egressed in the respective time window fromthe second port.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention can be obtained when thefollowing detailed description of the preferred embodiment is consideredin conjunction with the following drawings, in which:

FIG. 1 is an exemplary block diagram of a TS network;

FIG. 2 is an exemplary block diagram of a system for allowinginteroperability between networks;

FIG. 3 is an exemplary block diagram of a system for allowinginteroperability between networks;

FIG. 4 is an exemplary block diagram of a TS network interfacecontroller (NIC) according to one embodiment;

FIG. 5 illustrates an exemplary system for routing of tagged VLANpackets according to one embodiment;

FIG. 6 illustrates an exemplary system for routing of tagged VLANpackets according to another embodiment;

FIG. 7 illustrates an exemplary system for routing of tagged VLANpackets according to an embodiment;

FIG. 8 illustrates an exemplary system for routing of tagged VLANpackets according to an embodiment;

FIG. 9 is a flowchart diagram illustrating a method for routing oftagged VLAN packets according to one embodiment;

FIG. 10 is an exemplary block diagram of a TS NIC according to oneembodiment;

FIG. 11 illustrates an exemplary system for synchronizing clocks betweena TS and NTS network according to one embodiment;

FIG. 12 is a flowchart diagram illustrating a method for synchronizingclocks between a TS and NTS network according to one embodiment;

FIG. 13 is an exemplary block diagram of a TS network switch accordingto one embodiment;

FIG. 14 is an illustration of a time-based scheduled egress from a TSnetwork switch according to one embodiment; and

FIG. 15 is a flowchart diagram illustrating a method for scheduled dataegress from a TS network switch according to one embodiment.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and are herein described in detail. It should beunderstood, however, that the drawings and detailed description theretoare not intended to limit the invention to the particular formdisclosed, but on the contrary, the intention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the present invention as defined by the appended claims.

DETAILED DESCRIPTION Terms

The following is a glossary of terms used in the present application:

Computer System—any of various types of computing or processing systems,including a personal computer system (PC), mainframe computer system,workstation, network appliance, Internet appliance, personal digitalassistant (PDA), television system, grid computing system, or otherdevice or combinations of devices. In general, the term “computersystem” can be broadly defined to encompass any device (or combinationof devices) having at least one processor that executes instructionsfrom a memory medium.

Measurement Device—includes instruments, data acquisition devices, smartsensors, and any of various types of devices that are configured toacquire and/or store data. A measurement device may also optionally befurther configured to analyze or process the acquired or stored data.Examples of a measurement device include an instrument, such as atraditional stand-alone “box” instrument, a computer-based instrument(instrument on a card) or external instrument, a data acquisition card,a device external to a computer that operates similarly to a dataacquisition card, a smart sensor, one or more DAQ or measurement cardsor modules in a chassis, an image acquisition device, such as an imageacquisition (or machine vision) card (also called a video capture board)or smart camera, a motion control device, a robot having machine vision,and other similar types of devices. Exemplary “stand-alone” instrumentsinclude oscilloscopes, multimeters, signal analyzers, arbitrary waveformgenerators, spectroscopes, and similar measurement, test, or automationinstruments.

A measurement device may be further configured to perform controlfunctions, e.g., in response to analysis of the acquired or stored data.For example, the measurement device may send a control signal to anexternal system, such as a motion control system or to a sensor, inresponse to particular data. A measurement device may also be configuredto perform automation functions, i.e., may receive and analyze data, andissue automation control signals in response.

Functional Unit (or Processing Element)—refers to various elements orcombinations of elements. Processing elements include, for example,circuits such as an ASIC (Application Specific Integrated Circuit),portions or circuits of individual processor cores, entire processorcores, individual processors, programmable hardware devices such as afield programmable gate array (FPGA), and/or larger portions of systemsthat include multiple processors, as well as any combinations thereof.

Automatically—refers to an action or operation performed by a computersystem (e.g., software executed by the computer system) or device (e.g.,circuitry, programmable hardware elements, ASICs, etc.), without userinput directly specifying or performing the action or operation. Thusthe term “automatically” is in contrast to an operation being manuallyperformed or specified by the user, where the user provides input todirectly perform the operation. An automatic procedure may be initiatedby input provided by the user, but the subsequent actions that areperformed “automatically” are not specified by the user, i.e., are notperformed “manually”, where the user specifies each action to perform.For example, a user filling out an electronic form by selecting eachfield and providing input specifying information (e.g., by typinginformation, selecting check boxes, radio selections, etc.) is fillingout the form manually, even though the computer system must update theform in response to the user actions. The form may be automaticallyfilled out by the computer system where the computer system (e.g.,software executing on the computer system) analyzes the fields of theform and fills in the form without any user input specifying the answersto the fields. As indicated above, the user may invoke the automaticfilling of the form, but is not involved in the actual filling of theform (e.g., the user is not manually specifying answers to fields butrather they are being automatically completed). The presentspecification provides various examples of operations beingautomatically performed in response to actions the user has taken.

Concurrent—refers to parallel execution or performance, where tasks,processes, or programs are performed in an at least partiallyoverlapping manner. For example, concurrency may be implemented using“strong” or strict parallelism, where tasks are performed (at leastpartially) in parallel on respective computational elements, or using“weak parallelism”, where the tasks are performed in an interleavedmanner, e.g., by time multiplexing of execution threads.

Internet Protocol (IP)—refers to the networking model and a set ofprotocols for communication used for networks such as the Internet.

Transmission Control Protocol (TCP)—refers to a core protocol of theinternet protocol suite and provides delivery of a stream of octetsbetween programs running on computers connected to a local area network,intranet, or the public Internet.

Ethernet—refers to a family of computer networking technologies forlocal area networks (LANs) as standardized in IEEE 802.3.

Non-Time-Sensitive (NTS) Network—refers to a real-time Ethernet networkimplementation such as PROFINET, which uses standards such as TCP/IP andEthernet along with a mechanism for real time and isochronous real timecommunication, EtherCAT, which is an open high performanceEthernet-based fieldbus system, Ethernet/IP, which is designed for usein process control and other industrial automation applications,Ethernet Powerlink, which is a deterministic real-time protocol forstandard Ethernet, among others.

Local Area Network (LAN)—refers to a computer network that interconnectscomputers in a limited geographical area such as an office building oroffice complex.

Virtual Local Area Network (VLAN)—refers to a computer network that islogically segmented on an organizational basis, in other words,segmentation is based on functions or applications rather than on aphysical or geographic basis as is the case with LANs.

Media Access Control (MAC) Layer—refers to the sub-layer of amulti-layer computer network model which provides addressing and channelaccess control mechanisms that enable communication between multiplenetwork nodes that share a common medium, such as Ethernet. MAC layeracts as an interface between the logical link control sub-layer and thenetwork's physical (PHY) layer.

Time-Sensitive (TS) Network—refers to networks adhering to the IEEE802.1 standard for real-time data transfer.

Time-Sensitive (TS) Packet—refers to specific packets of data routedthrough a TS network that contain time-sensitive data. May includepackets from an NTS network with a VLAN tag inserted using embodimentsof the present invention.

Isochronous—refers generally to events that occur regularly, or in otherwords, at equal time intervals.

Asynchronous—refers generally to events that occur irregularly, or inother words, at unscheduled and intermittent time intervals.

FIG. 1—Exemplary TS Network

FIG. 1 illustrates an exemplary block diagram of a time-sensitive (TS)network. The TS network switch 100 may be configured in accordance withvarious embodiments of the present invention as described below in moredetail. Additionally, TS network nodes, such as TS network nodes 115,125, 135, and 175 may be configured according to various embodiments asdescribed below in more detail.

As FIG. 1 shows, in one embodiment, the TS network switch 100 mayinclude a plurality of ports, e.g., 110 a to 110 f, coupled to afunctional unit. The term functional unit is used in its broadest senseand refers to various elements or combinations of elements, such as, forexample, circuits such as an ASIC (Application Specific IntegratedCircuit), portions or circuits of individual processor cores, entireprocessor cores, individual processors, programmable hardware devicessuch as a field programmable gate array (FPGA), and/or larger portionsof systems that include multiple processors, as well as any combinationsthereof.

In certain embodiments, the TS network switch may be included in asystem for interoperating between a TS network and a non-time-sensitive(NTS) network, such as NTS networks 145 and 155. The termnon-time-sensitive network, or NTS network, refers to a proprietaryreal-time Ethernet implementation, such as PROFINET, which usesstandards such as TCP/IP and Ethernet along with a mechanism for realtime and isochronous real time communication, EtherCAT, which is an openhigh performance Ethernet-based fieldbus system, Ethernet/IP, which isdesigned for use in process control and other industrial automationapplications, or Ethernet Powerlink, which is a deterministic real-timeprotocol for standard Ethernet, among others. Additionally, anyreference to an NTS device, such as an NTS node or an NTS timekeeper,refers generally to a device that would be compatible with an NTSnetworks.

In such embodiments, a first port, such as port 110 c, of the pluralityof ports 110 a to 110 f, may be configured to couple to an NTS node ofan NTS network, such as a node of NTS network 155. Furthermore, thefunctional unit may be configured to insert a virtual local area network(VLAN) tag indicating the NTS network, e.g., NTS network 155, into eachNTS packet received from the NTS network by the first port, e.g., port110 c, before routing each NTS packet to one or more other ports of theplurality of ports, e.g., ports 110 a, 110 b, 110 d, 110 e, or 110 f, inthe TS network switch 100. Additionally, the functional unit may beconfigured to remove the VLAN tag from each received VLAN tagged NTSpacket before forwarding, via the first port (port 110 c) each receivedVLAN tagged NTS packet to the NTS node of the NTS network, e.g., NTSnetwork 155.

In some embodiments, a second port, such as port 110 d or 110 f, may beconfigured to couple to a TS network interface controller (NIC), such asthe TS NIC included in TS network nodes 115 and 175. In suchembodiments, the functional unit may be configured to receive, via thesecond port, one or more of the tagged NTS packets from the first portand forward, via the second port, the one or more tagged NTS packets tothe TS NIC. Additionally, the functional unit may be configured toreceive, via the second port, tagged NTS packets from the TS NIC androute tagged NTS packets to the first port.

In some embodiments, the functional unit of the TS network switch 100may be coupled to a plurality of queues which may also be coupled to theplurality of ports. Additionally, in some embodiments, each port may beassociated with a respective set of network addresses for TS packets.Also, each TS packet may have a destination address and a type thatspecifies a respective egress period. An egress period may specify arespective time window and frequency for egressing TS packets to networknodes based on the type of the TS packets. Further, each queue may beassociated with a respective TS packet type and a respective port of theplurality of ports of the TS network switch 100.

In certain embodiments, the functional unit may be configured to receiveone or more TS packets asynchronously from a network node, such as, forexample, TS network node 115 or 175 or an NTS node of NTS network 155,via a first port, such as port 110 c, 110 d, or 110 f. Additionally, thefunctional unit may be configured to determine a second port foregressing at least one of the one or more TS packets based on thedestination address of the at least one TS packet, and in someembodiments, determine an egress period for egressing the at least oneTS packet based on the type of the at least one TS packet. Subsequently,the functional unit may be configured to determine that the at least oneTS packet cannot currently be egressed from the second port and, inresponse, the functional unit may queue the at least one TS packet in afirst queue of the plurality of queues based on the respective TS packettype and destination address, where the first queue may be associatedwith the second port. Finally, the functional unit may egress the atleast one TS packet in the respective time window from the second port.

In some embodiments, the TS network node, e.g., TS network node 135 or175, may include a TS NIC. In other embodiments, the TS network node,e.g., TS network node 115 or 125, may include a TS NIC and a TS networkswitch. In certain embodiments, the TS NIC may include a plurality ofNTS receive packet queues and a corresponding plurality of NTS transmitpacket queues, a port, and a functional unit. The TS NIC may beconfigured to couple to a port of a TS network switch via the port ofthe TS NIC, such as the coupling of port 175 a of TS network node 175 toport 110 d of TS network switch 100, or the coupling of port 115 a of TSnetwork node 115 to port 110 f of TS network switch 100, or port 125 aof TS network node 125 to port 115 b of TS network node 115, or port 135a of TS network node 135 to port 125 b of TS network node 125.Additionally, in some embodiments, the functional unit of the TS NIC maybe configured to queue tagged NTS packets received via the port in anNTS receive packet queue corresponding to an NTS network, such as NTSnetwork 145 or 155, for subsequent provision to a device coupled to theTS NIC. Also, the functional unit of the TS NIC may be configured toqueue NTS packets received from a device coupled to the TS NIC for therespective NTS networks.

In certain embodiments, the TS NIC may also include a clock, such as theclocks illustrated in TS network nodes 115, 125, 135, and 175. The clockmay be synchronized to a master clock, such as the clock illustrated inTS network switch 100, e.g., a TS network master clock. In turn, themaster clock, such as the TS network master clock illustrated in TSnetwork switch 100, may be synchronized to a global clock accessible viaa local area connection (LAN) or the Internet, such as the clock ofInternet/LAN 165. In other embodiments, the master clock may be a clocketernal to the TS network, such as a clock of an NTS network timekeeper.Additionally, the TS NIC may include a plurality of queue pairs forsegregation of VLAN packets based on VLAN tags as described above. Insome embodiments, each queue pair may include an input/output queue pairand at least one queue pair may correspond to a NTS network, such as NTSnetwork 145 or 155. Further, the TS NIC may include a time stamp unit(TSU) coupled to the clock. In some embodiments, the TSU may beconfigured to communicate with the NTS network via the at least onequeue pair and synchronize a clock of an NTS timekeeper, such as theclocks illustrated as part of NTS networks 145 and 155. As used herein,a timekeeper is a clock that is synchronized to a master clock. Incertain embodiments, the TSU may be configured to generate time stampsfor synchronization packets in accordance with the clock synchronized tothe master clock. In such embodiments, the synchronization packets maybe usable by an NTS network timekeeper to synchronize the NTS network tothe master clock.

FIGS. 2-9: Systems and Methods for Interoperability Between Networks

Embodiments of the systems and methods described herein may allow forthe interoperability between time-sensitive (TS) networks, e.g.,networks conforming to the IEEE 802.1 standard for real-time datatransfer, and non-time sensitive (NTS) networks, e.g., real-time datatransfer networks not conforming to the IEEE 802.1 standard forreal-time data transfer. Examples of NTS networks include PROFINET,which uses standards such as TCP/IP and Ethernet along with a mechanismfor real time and isochronous real time communication, EtherCAT, whichis an open high performance Ethernet-based fieldbus system, Ethernet/IP,which is designed for use in process control and other industrialautomation applications, Ethernet Powerlink, which is a deterministicreal-time protocol for standard Ethernet, among others. As mentionedpreviously, NTS networks are not generally interoperable amongthemselves or with TS networks due to the proprietary implementation ofthe media access control (MAC) layer of each NTS network. Embodiments ofthe systems and methods below allow for such interoperability between TSand NTS networks and also amongst NTS networks.

FIGS. 2-3: Exemplary Systems for Interoperability Between Networks

FIG. 2 is a block diagram of an exemplary system for interoperabilitybetween networks, such as TS network 350 and NTS network 250. It shouldbe noted that although TS network 350 is illustrated as encompassing TSnetwork switch 200, TS NIC 300, and device 325, it is envisioned that TSnetwork 350 may include one or more TS network switches, one or more TSnetwork nodes, such as TS NICs, and one or more devices. In someembodiments the system for interoperating between a TS network, such asTS network 350, and an NTS network, such as NTS network 250, may includea TS network switch, such as TS network switch 200, and a TS NIC, suchas TS NIC 300.

In an exemplary embodiment, the TS network switch 200 may include aplurality of ports 210 a-210 e and a functional unit 205 coupled to theplurality of ports. A first port, e.g., port 210 a, may be configured tocouple to an NTS node of an NTS network, such as NTS network 350. Thefunctional unit 205 may be configured to insert a VLAN tag indicatingNTS network 350 into each NTS packet received from NTS network 250 byport 210 a, before routing each NTS packet to one or more other ports ofthe plurality of ports, e.g., ports 210 b-210 e, thereby generatingtagged NTS packets. Further, the functional unit 205 may be configuredto remove the VLAN tag from each received VLAN tagged NTS packet beforeforwarding, via the first port, each received VLAN tagged NTS packet tothe NTS node of NTS network 250.

Additionally, a second port, such as port 210 e, may be configured tocouple to a TS NIC, such as TS NIC 300. The functional unit 205 may beconfigured to receive, via the second port, one or more of the taggedNTS packets from the first port (e.g., port 210 a), and forward, via thesecond port, the one or more tagged NTS packets to the TS NIC.Additionally, the functional unit 205 may be configured to receive, viathe second port, tagged NTS packets from the TS NIC and route tagged NTSpackets to the first port.

Further, the TS NIC, e.g., TS NIC 300, may include a plurality of NTSreceive packet queues, e.g., queues 320 a-320 n. Each NTS receive packetqueue may be configured to store received packets from respective NTSnetworks. For example, a first NTS receive packet queue, such as NTSreceive packet queue 320 a of TS NIC 300, may be configured to storepackets received from the NTS network, e.g., NTS network 250.Additionally, the TS NIC may include a corresponding plurality of NTStransmit packet queues, e.g., queues 330 a-330 n. Each NTS transmitpacket queue may be configured to store packets received from a device,such as device 325, coupled to the TS NIC for the respective NTSnetworks. Thus, for example, NTS transmit packet queue 330 a maycorrespond to queue 320 a and store packets for transmission to NTSnetwork 250.

Note that device 325 may be or include instruments, data acquisitiondevices, smart sensors, and any of various types of devices that areconfigured to acquire and/or store data. In other words, device 325 maybe or include a measurement device or multiple measurement devices.

In certain embodiments, additional ports of the TS network switch, e.g.,one or more other ports of the plurality of ports of the TS networkswitch, such as ports 210 b-210 d of TS network switch 200, may each beconfigured to couple to a corresponding other NTS network, e.g., an NTSnetwork other than the NTS network coupled to the first port. In otherwords, exemplary ports 210 b-210 d may be configured to couple to acorresponding NTS network. In such embodiments, functional unit 205 maybe further configured to insert a VLAN tag into each NTS packet receivedby each of the additional ports from the NTS node of the correspondingNTS network before routing each NTS packet to one or more ports of theplurality of ports in the TS network switch. In these embodiments, theVLAN tag indicates the respective, or corresponding, NTS network.Additionally, functional unit 205 may be configured to remove the VLANtag from received VLAN tagged NTS packets before forwarding, via theappropriate additional port, each of the received VLAN tagged NTSpackets to the respective NTS node of the corresponding NTS network. Inthis manner, interoperability between the TS network and a plurality ofNTS networks may be achieved.

Additionally, the TS NIC may include a functional unit 305 coupled tothe plurality of received packet queues 320 a-320 n, and the pluralityof transmit packet queues 330 a-330 n. Also, the TS NIC may include aport 310 a coupled to the functional unit, the plurality of receivedpacket queues 320 a-320 n, and the plurality of transmit packet queues330 a-330 n. In some embodiments, a TS network node may include the TSNIC 300. In other embodiments, a TS network node may include both the TSNIC 300 and the TS network switch 200.

In an exemplary embodiment, the functional unit 305 of the TS NIC 300may be configured to queue tagged NTS packets received via port 310 a inNTS receive packet queue 320 a for subsequent provision to device 325.Additionally, the functional unit 305 may be configured to queue NTSpackets received from device 325 in NTS transmit packet queue 330 a andinsert the VLAN tag indicating NTS network 250 into each packet receivedfrom NTS transmit packet queue before forwarding, via port 310 a, eachNTS packet to port 210 e of TS network switch 200, thereby generatingtagged NTS packets.

In further embodiments, a TS network node may include a TS NIC, such asTS NIC 300. Additionally, the TS network node may include a device, suchas device 325. In an exemplary embodiment, the device may be or includean embedded device. The embedded device may include one or moremeasurement devices.

Further, in some embodiments, the TS network node may include both a TSNIC, such as TS NIC 300, and a TS network switch, such as TS networkswitch 200. In such embodiments, the TS network node may also include adevice, such as device 325. In an exemplary embodiment, the device mayinclude an embedded device. In some embodiments, the embedded device mayinclude one or more measurement devices. Additionally, in someembodiments, the TS network node may be configured as a bridge between aTS network and an NTS network. The system may further include one ormore additional TS network nodes, which in conjunction with the TSnetwork node, form a plurality of TS network nodes. Each TS network nodemay include a TS NIC and a TS network switch with the functionalitiesdisclosed above, and each TS network node of the plurality of TS networknodes may be configured as a bridge between the TS network and arespective NTS network. In other words, each TS network node may becoupled to an NTS network, and thus, there may be a corresponding NTSnetwork for each TS network node. In this manner, interoperabilitybetween the TS network and a plurality of NTS networks may be achieved.

FIG. 3 is a block diagram of another exemplary system forinteroperability between networks, such as TS network 355 and NTSnetwork 250. Note that blocks with similar or the same functionality asblocks previously described above in reference to FIG. 2 are labeledsimilarly. Thus, NTS network 250 may have the same or similarfunctionality as NTS network 250 of FIG. 2. Similarly, device 325 ofFIG. 2 may have the same or similar functionality as device 325 of FIG.3.

In an exemplary embodiment, a time-sensitive (TS) network node 400 forinteroperating between a TS network, e.g., TS network 355, and an NTSnetwork, e.g., NTS network 250, may include a functional unit 405 and aplurality of ports, e.g., ports 410 a-410 e, coupled to functional unit405. A first port, e.g., port 410 a, may be configured to couple to anNTS network node of NTS network 250. Additionally, TS network node 400may include a plurality of NTS receive packet queues, e.g., queues 420a-420 n, coupled to functional unit 405. The NTS receive packet queuesmay be configured to store received packets from respective NTSnetworks, where a first NTS receive packet queue, e.g., NTS receivepacket queue 420 a, corresponds to NTS network 250. TS network node 400may further include a plurality of NTS transmit packet queues, e.g.,queues 430 a-430 n, coupled to functional unit 405. The NTS transmitpacket queues may be configured to store packets received from a devicecoupled to TS network node 400, such as device 325. Thus, for example,NTS transmit packet queue 430 a may correspond to queue 420 a and storepackets for transmission to NTS network 250.

In some embodiments, functional unit 405 may be configured tocommunicate tagged NTS packets with the TS network 355 via a secondport, e.g., one of ports 410 b-410 e. In such embodiments, the secondport, e.g., port 410 b, may be configured to couple to another TSnetwork node of the TS network and functional unit 405 may forward NTSpackets received from NTS network 250 to the TS network via the secondport. Additionally, the second port, e.g., port 410 b, may be configuredto receive NTS packets from the TS network and the functional unit mayforward the NTS packets received via the second port to the first port.

Further, functional unit 405 may be configured to insert a VLAN tagindicating NTS network 250 into each NTS packet received from the NTSnetwork by the first port, e.g., port 410 a, before routing each NTSpacket to either the second port, e.g., port 410 b, one or more otherports of the plurality of ports, e.g., ports 410 c-410 e, or to thefirst NTS receive packet queue, e.g., queue 420 a, thereby generatingtagged NTS packets. Also, the functional unit may be configured toremove the VLAN tag from each VLAN tagged NTS packet received by thesecond port (e.g., port 410 b), the one or more other ports (e.g., ports410 c-410 e), or from the NTS transmit packet queue that corresponds tothe first NTS receive packet queue, e.g., queue 430 a, beforeforwarding, via the first port (e.g., port 410 a), each received VLANtagged NTS packet to the NTS node of NTS network 250.

In certain embodiments, functional unit 405 may be configured to queueat least a subset of tagged NTS packets received by TS network node 400in NTS receive packet queue 420 a for subsequent provision to device325. Additionally, functional unit 405 may be configured to queue NTSpackets received from device 325 in NTS transmit packet queue 430 abefore forwarding each NTS packet to port 410 a, thereby generatingtagged NTS packets.

It should be noted that the number and labels of the various ports,queues, and networks disclosed herein are exemplary only, and are notintended to limit the ports, queues, and networks to any particularnumber, form, or function.

FIGS. 4-8: Exemplary Implementations of Devices and Systems forInteroperability Between Networks

FIGS. 4 through 8 illustrate implementations of embodiments of thepresent techniques to allow interoperability between networks. Theimplementations described herein are for explanation purposes only andare not intended to limit the scope of the present invention to anyparticular form, architecture, or functionality. Each implementation mayuse all or a portion of the embodiments described above in reference toFIGS. 1-3.

FIG. 4 is a high level block diagram of an exemplary implementation of aTS network interface controller (NIC) with support for a TS network. Insome embodiments, the TS NIC may be included in a TS network node.Additionally, the TS network node may include or be coupled to a device,such as a measurement device. In some embodiments, the device mayinclude an embedded device which may include a physical interface and abus/memory interface, including an application and configurationinterface.

The TS NIC may include a functional unit configured to implement thelogic described herein. For example, the functional unit may beconfigured to control the VLAN data management block as well as thedynamic memory access (DMA) block. Additionally, the functional unit maybe coupled to and communicate with the physical layer (PHY), the mediaaccess layer (MAC), and time stamp unit(s) (TSU) of the TS NIC. Notethat in some embodiments, the PHY may include a TSU.

In some embodiments, the functional unit, via the VLAN data managementblock, may segregate traffic based on VLAN tags, such as the VLAN tagsdescribed above. The VLAN data management block may be coupled to aplurality of transmit (Tx) queues and a plurality of receive (Rx)queues. In some embodiments, a subset of the Tx queues may include aplurality of NTS transmit packet queues. Similarly, a subset of the Rxqueues may include a plurality of NTS receive packet queues. The DMAblock may be configured via software to read and write data to theembedded device via the application interface. Data received by the NIC,such as tagged NTS packets, are routed to the VLAN Data Management blockwhich segregates the data into the appropriate Rx queue. Then, the DMAblock may read the data from the Rx queue and write the data to theembedded device. Additionally, the embedded device may generate datawhich is read by the DMA block and written to the appropriate Tx queue.

FIG. 5 is an example topology of a system allowing interoperabilitybetween a TS network and an NTS network, although the topology shown,and the various elements included therein, are meant to be exemplaryonly. The TS network may include a TS network switch which allows theinteroperability between the TS and the NTS network. The TS networkswitch may include any features, in any combination, of the embodimentsdescribed above in reference to TS network switches 100, 200, and 400.The TS network switch 500 may include multiple ports, e.g., ports A-E.In the embodiment shown, ports A, B, and E are each coupled to a TSnetwork node. Port A may be coupled to TS node 530 which may be similarand have the same or similar functionality to TS NIC 300 or thefunctionality described above in reference to the TS NIC of FIG. 4. Inthis particular example, TS node 530 may be coupled to embedded deviceEB530. Note, however, that TS node 530 may alternatively includeembedded device EB530. Similar to port A, port B may be coupled to TSnode 540, where TS node 540 may have similar or the same functionalityas TS node 530. TS node 540 may be coupled to or include embedded deviceEB540. Additionally, port E may be coupled to TS node 520. TS node 520may include both a TS NIC and a TS network switch. The TS NIC of TS node520 may be coupled to or include embedded device EB520. Further, asdisclosed above, TS node 520 may have multiple functional units or asingle functional unit. In other words, TS node 520 may include a firstfunctional unit to control the TS network switch and a second functionalunit to control the TS NIC or TS node 520 may have a single functionalunit to control both the TS NIC and TS network switch. Also, TS node 520may be configured as a bridge and may be coupled to TS node 510 via aport of the TS network switch of TS node 520. TS node 510 may be similarto TS node 520 and include both a TS NIC and TS network switch. Embeddeddevice EB510 may be included in or coupled to TS node 510.

Ports D and C of the TS network switch may be coupled to networks ornodes other than TS networks or TS network nodes. For example, port Dmay be coupled to an Ethernet network, such as Internet/LAN 165 whereasport C may be coupled to an NTS node of an NTS network, such as NTS node550. NTS node 550 may include or be coupled to embedded device EB550.Further, NTS node 550 may be configured as a bridge to NTS node 560which may be coupled to or include embedded device EB560. In otherwords, NTS node 510 may include both a NIC and a switch.

In order to allow interoperability between the TS network, e.g., TSnodes 510-540, and the NTS network, e.g., NTS nodes 550 and 560, TSnetwork switch 500 may include or implement embodiments of the inventionas described above. For example, a functional unit of TS network switch500 may be configured to insert a VLAN tag into each packet received viaport C. In other words, each packet received from the NTS network wouldbe tagged, for example with “VLAN 3”. Further, the functional unit ofthe TS network switch may be configured to remove VLAN tags from eachpacket received via port A before forwarding each packet to the NTSnetwork via port C. Thus, packets received via port A and containing thetag “VLAN 3” would have the tag removed prior to the packet beingforwarded to the NTS network via port C. Note that in the configurationas described, only port A may egress packets tagged with “VLAN 3”, e.g.,packets received from the NTS network via port C. All other ports areconfigured to discard packets with the “VLAN 3” tag.

As previously mentioned, each TS network node may be configured with anyof the features of the embodiments described above. For example, TS node530, coupled to port A, may include a functional unit configured tosegregate and queue network packets based on VLAN tags. Thus, the TS NICof TS node 530 may include a plurality of NTS receive packet queues andeach NTS receive packet queue may be configured to store receivedpackets from respective NTS networks, including a first NTS receivepacket queue configured to store packets received from the NTS network.Additionally, the TS NIC may include a corresponding plurality of NTStransmit packet queues, and each NTS transmit packet queue may beconfigured to store packets received from EB530 for the respective NTSnetworks. Thus, a first NTS transmit packet queue may correspond to thefirst NTS receive packet queue and store packets for transmission to theNTS network. Also, the functional unit of the TS node 530 may be coupledto the plurality of NTS receive packet queues and the plurality of NTStransmit packet queues and configured to queue tagged NTS packetsreceived from port A in the first NTS receive packet queue forsubsequent provision to EB530. Additionally, the functional unit may beconfigured to queue NTS packets received from EB530 in the first NTStransmit packet queue and insert the VLAN tag indicating the NTSnetwork, e.g., “VLAN 3,” into each packet received from the first NTStransmit packet queue before forwarding the NTS packet to port A of TSnetwork switch 500.

FIG. 6 is an example of an alternate topology of a system allowinginteroperability between a TS network and an NTS network. In such atopology, the TS network may include one or more TS network nodes andswitches, such as TS nodes 610-630 and TS network switch 600. Note thatembedded devices EB610-630 may be included in or coupled to respectiveTS nodes 610-630. Additionally, as shown, TS node 630 may be configuredas a bridge between the TS network and the NTS network, which mayinclude NTS nodes 640-650 where embedded devices EB640 and EB650 areincluded in or coupled to respective NTS nodes 640 and 650. In order forTS node 630 to function as a bridge between the TS and NTS networks, itmay include both a TS network switch and TS NIC configured withembodiments of the present invention to allow VLAN tagging of NTSpackets received from the NTS network, e.g., NTS node 640. Additionally,TS node 620 may also include a TS network switch and TS NIC configuredwith embodiments of the present invention to allow forwarding of VLANtagged NTS packets to other destinations within the TS network, such asTS node 610 via TS network switch 600, which each may includeembodiments of the present invention to allow forwarding and segregationof VLAN tagged NTS packets.

FIG. 7 is an example topology of another alternate system allowinginteroperability between a TS network and NTS networks. In such atopology, the system may include multiple TS network nodes, each coupledto a respective NTS network. Thus, for example, TS node 720 may becoupled to an NTS network that includes NTS nodes 722-728, TS node 730may be coupled to an NTS network that includes NTS nodes 732-738, and TSnode 740 may be coupled to an NTS network that includes NTS nodes742-748. Additionally, each NTS network may be assigned a specific VLANtag indicating the NTS network. For example, packets received from NTSnode 722 may be tagged with a “VLAN 2” tag whereas packets received fromNTS node 732 may be tagged with a “VLAN 3” tag and packets received fromNTS node 742 may be tagged with a “VLAN 4” tag. Further, each of the TSnodes 720-740 may include both a TS NIC and a TS network switch, eachconfigured according to an embodiment of the present invention allowingfor the management of tagged NTS packets. Also, TS node 710, which maybe coupled to or include embedded device 710, may be configuredaccording to an embodiment of the present invention to manage NTSpackets received from each of the respective NTS networks. Thus, TS node710 may be configured with a respective NTS receive packet queue and arespective NTS transmit packet queue for each respective NTS network. Inother words, TS node 710 may include a send/receive queue pairassociated with each VLAN tag, e.g., a send/receive queue pair for “VLAN2” tagged packets, a send/receive queue pair for “VLAN 3” taggedpackets, and a send/receive queue pair for “VLAN 4” tagged packets.Additionally, TS node 710 may include a send/receive queue pair for TSpackets, such as those generated by real-time camera 750 and asend/receive queue pair for Ethernet packets, such as those received viaTS node 720 from Internet/LAN 165.

FIG. 8 is an example topology of yet another alternate system allowinginteroperability between a TS network and NTS networks. In such asystem, the interoperability between the TS network and the NTS networksis managed by TS network switch 800 configured in accordance with anembodiment of the present invention. Thus, TS network switch 800 may beconfigured to tag packets received from NTS network 830 with a “VLAN 3”tag, packets received from NTS network 840 with a “VLAN 2” tag, andpackets received from NTS network 850 with a “VLAN 1” tag. Also, similarto TS node 710, TS nodes 810 and 820 may be configured to segregatepackets received from and destined for each NTS network in respectivesend/receive queue pairs while also segregating TS network packets andEthernet packets received via TS network switch 800 from Internet/LAN165.

FIG. 9—Flowchart of a Method for Interoperating Between a TS Network andan NTS Network

FIG. 9 illustrates a method for interoperating between a TS network andan NTS network, according to one embodiment. As described above, a TSnetwork refers to a network adhering to the IEEE 802.1 standard forreal-time data transfer whereas an NTS network refers to a real-timeEthernet network implementation such as PROFINET, which uses standardssuch as TCP/IP and Ethernet along with a mechanism for real time andisochronous real time communication, EtherCAT, which is an open highperformance Ethernet-based fieldbus system, Ethernet/IP, which isdesigned for use in process control and other industrial automationapplications, or Ethernet Powerlink, which is a deterministic real-timeprotocol for standard Ethernet, among others. The method shown in FIG. 9may be used in conjunction with any of the systems or devices shown inany of the Figures described herein, among other devices. In variousembodiments, some of the method elements shown may be performedconcurrently, in a different order than shown, or may be omitted.Additional method elements may also be performed as desired. As shown,this method may operate as follows.

First, in 902 a TS network switch may be configured. The TS networkswitch may be similar to the TS network switches described above and mayinclude a plurality of ports and a first functional unit coupled to theplurality of ports. Elements 912-962 may be performed in order toconfigure the TS network switch.

In 912, a first port of the plurality of ports may be configured tocouple to an NTS node of the NTS network.

In 922, a second port of the plurality of ports may be configured tocouple to a TS NIC similar to the TS NICs described above.

In 932, the first functional unit may be configured to insert a VLAN tagindicating the NTS network into each NTS packet received from the NTSnetwork by the first port before routing each NTS packet to one or moreother ports of the plurality of ports in the TS network switch, therebygenerating tagged NTS packets.

In 942, the first functional unit may be configured to remove the VLANtag from each received VLAN tagged NTS packet before forwarding, via thefirst port, each received VLAN tagged NTS packet to the NTS node.

In 952, the first functional unit may be configured to receive one ormore of the tagged NTS packets from the first port and forward, via thesecond port, the one or more tagged NTS packets to the TS NIC.

In 962, the first functional unit may be configured to receive, by thesecond port, tagged NTS packets from the TS NIC and route tagged NTSpackets to the first port.

In 904, the TS NIC may be configured. As mentioned, the TS NIC may besimilar to the TS NICs described above and may include a secondfunctional unit, a third port, a plurality of NTS receive packet queues,and a corresponding plurality of NTS transmit packet queues. Elements914-924 may be performed in order to configure the TS network switch.

In 914, the second functional unit may be configured to queue tagged NTSpackets received via the third port in the first NTS receive packetqueue for subsequent provision to the device coupled to the TS NIC.

In 916, the second functional unit may be configured to queue NTSpackets received from the device coupled to the TS NIC in the first NTStransmit packet queue and insert the VLAN tag indicating the NTS networkinto each NTS packet received from the first NTS transmit packet queuebefore forwarding, via the third port, each NTS packet to the secondport, thereby generating tagged NTS packets.

In some embodiments, the method may further include the first functionalunit inserting the VLAN tag indicating the NTS network into each NTSpacket received by the first port from the NTS network before routingeach NTS packet to one or more other ports of the plurality of ports inthe TS network switch, thereby generating tagged NTS packets. In suchembodiments, the first functional unit may also remove the VLAN tag fromeach received VLAN tagged NTS packet by the first port before forwardingeach received VLAN tagged NTS packet to the NTS node. Further, the firstfunctional unit may receive one or more of the tagged NTS packets fromthe first port and forward, via the second port, the one or more taggedNTS packets to the TS NIC. In addition, the first functional unit mayreceive, via the second port, tagged NTS packets from the TS NIC andthen may route the tagged NTS packets to the first port.

Additionally, the second functional unit may queue tagged NTS packetsreceived via the third port in the first NTS receive packet queue forsubsequent provision to the device coupled to the TS NIC. Also, thesecond functional unit may queue NTS packets received from the devicecoupled to the TS NIC in the first NTS transmit packet queue and mayinsert the VLAN tag indicating the NTS network into each NTS packetreceived from the first NTS transmit packet queue before forwarding, viathe third port, each NTS packet to the second port.

In certain embodiments, the method may further include configuring eachof another one or more other ports of the plurality of ports of the TSnetwork switch to couple to a corresponding other NTS network via arespective NTS node of the corresponding other NTS network. In suchembodiments, the first functional unit may be further configured toinsert a VLAN tag into each NTS packet received via each of the anotherone or more other ports from the NTS node of the corresponding other NTSnetwork before routing each NTS packet to one or more ports of theplurality of ports in the TS network switch, where the VLAN tagindicates the respective NTS network, thereby generating tagged NTSpackets. In addition, the first functional unit may be furtherconfigured to remove the VLAN tag from received VLAN tagged NTS packetsbefore forwarding, via each of the another one or more other ports, eachof the received VLAN tagged NTS packets to the respective NTS node ofthe corresponding other NTS network. Further, in some embodiments, themethod may include coupling each of the another one or more other portsto the corresponding other NTS network via the respective NTS node ofthe corresponding other NTS network.

Additionally, the first functional unit may insert a VLAN tag into eachNTS packet received via each of the another one or more other ports fromthe NTS node of the corresponding other NTS network before routing eachNTS packet to one or more ports of the plurality of ports in the TSnetwork switch, where the VLAN tag indicates the respective NTS network,thereby generating tagged NTS packets. Similarly, the first functionalunit may remove the VLAN tag from received VLAN tagged NTS packetsbefore forwarding, via each of the another one or more other ports, eachof the received VLAN tagged NTS packets to the respective NTS node ofthe corresponding other NTS network.

FIGS. 10-12: Systems and Methods for Synchronizing a Master ClockBetween Networks

The systems and methods described below may allow for thesynchronization between non-time sensitive (NTS) networks, e.g.,real-time data transfer networks not conforming to the IEEE 802.1standard for real-time data transfer and time-sensitive networks, e.g.,networks conforming to the IEEE 802.1 standard for real-time datatransfer, and non-time sensitive (NTS) networks. Most NTS networksimplement a proprietary clock synchronization scheme, thus, in order tobe fully interoperative with a TS network, the TS network clocksynchronization may be required to be mapped to each NTS network coupledto the TS network. The systems and methods below allow for clocksynchronization between TS and NTS networks.

FIG. 10: Exemplary Block Diagram of a TS NIC

FIG. 10 is a block diagram of an exemplary TS NIC for synchronizingclocks between a TS and an NTS network. TS NIC 1000 may be similar tothe TS NICs described above. In some embodiments the TS NIC 1000 mayinclude a functional unit, such as functional unit 1030, coupled to aport, such as port 1010. Additionally, the TS NIC may include a clock,such as clock 1032 coupled to the functional unit and synchronized to amaster clock, such as Master Clock 1052 of TS network 1050. In someembodiments, the master clock may be included in a TS network switch ofthe TS network. In other embodiments, the master clock may be externalto the TS network, such as a NTS network timekeeper. In certainembodiments, the master clock may be synchronized to a global clockexternal to the TS network.

The clock may also be coupled to a time stamp unit (TSU), such as TSU1034. The TSU may also be coupled to the functional unit. In someembodiments, the TSU may be included in the physical layer of the TSNIC. Further, the TS NIC may include a plurality of input/output queuepairs, such as queues 1020 a-1020 n and 1040 a-1040 n coupled to thefunctional unit and the port, for segregation of virtual local areanetwork (VLAN) packets based on VLAN tags, wherein each input/outputqueue pair corresponds to a respective non-time-sensitive (NTS) network.For example, input queue 1020 a may have a corresponding output queue1040 a, and both may correspond to NTS network 1060. Additionally, theinput queues may be NTS receive packet queues as discussed above and theoutput queues may be NTS transmit packet queues as discussed above.

For each of the respective NTS networks, the functional unit may beconfigured to generate synchronization packets usable by an NTS networktimekeeper, e.g., a clock that is synchronized to a master clock, of therespective NTS network to synchronize the NTS network to the masterclock, including using the TSU to generate time stamps for thesynchronization packets in accordance with the clock synchronized to themaster clock and communicate with the respective NTS network via theport using the corresponding input/output queue pair, including sendingthe synchronization packets to the NTS network timekeeper of therespective NTS network. In an exemplary embodiment, the first functionalmay be further configured to egress the synchronization packets via theoutput queue of the at least one input/output queue pair based on aspecified egress period, wherein the specified egress period specifies atime window and frequency for egressing the synchronization packets.

Thus, for example, functional unit 1030 may generate synchronizationpackets usable by NTS timekeeper 1062 of NTS network 1060 to synchronizeNTS network 1060 to master clock 1052 of TS network 1050. To generatethe synchronization packets, functional unit 1030 may use TSU 1034 togenerate time stamps for the synchronization packets in accordance clock1032, synchronized to master clock 1052 of TS network 1050. Then,functional unit 1030 may communicate with NTS network 1060 via port 1010using input queue 1020 a and output queue 1040 a, including sending thesynchronization packets to NTS timekeeper 1062 of NTS network 1060.

It should be noted, that TS network 1050 may be required to includeembodiments of the functionality discussed above to allow for theinteroperability between TS network 1050 and 1060. Thus, thesynchronization packets sent by TS NIC 1000 may be VLAN tagged NTSpackets as described in detail above.

In some embodiments, the TS NIC may be included in a TS network node. Inone embodiment, the TS network node may include the TS NIC and a TSnetwork switch.

FIG. 11: Exemplary System for Synchronizing Clocks Between a TS and NTSNetworks

FIG. 11 is an illustration of an exemplary system for synchronizingclocks between a TS network and multiple NTS networks. As shown, thesystem may include TS network switch 1100 and TS nodes 1110 and 1120. TSnetwork switch 1100 may be similar in functionality to the TS networkswitches previously described. Thus, TS network switch may include afunctional unit configured to manage VLAN tags and data flow between aTS network and one or more NTS networks. In this particular example, TSnetwork switch 1100 includes ports A-E. Port B may be configured tocouple to NTS network 1130 which includes NTS nodes 1132-1138. Thus, thefunctional unit may be configured to insert a VLAN tag indicating NTSnetwork 1130 in packets received from NTS node 1132 via port B.Similarly, port C may be configured to couple to NTS network 1140 whichincludes NTS nodes 1142-1148. Thus, the functional unit may also beconfigured to insert a VLAN tag indicating NTS network 1140 in packetsreceived from NTS node 1142 via port C.

TS nodes 1110 and 1120 may each include a TS NIC configured similarly toTS NIC 1000 of FIG. 10. Therefore, TS nodes 1110 and 1120 may eachinclude a clock synchronized to a master clock. In this particularexample, the clock included in TS network switch 1100 may be configuredas the master clock, e.g., the TS network master clock. Thus, the clocksof TS nodes 1110 and 1120 may each be synchronized to the clock of TSnetwork switch 1100. Note that since TS nodes 1110 and 1120 eachincludes a clock synchronized to a master clock, both are consideredtimekeepers of the TS network. Additionally, the master clock of TSnetwork switch 1100 may be synchronized to a global clock, such as theglobal clock of Internet/LAN 165.

Further, TS node 1120 may be configured to propagate its clock viasynchronization packets to NTS node 1132, the timekeeper of NTS network1130. Additionally, TS node 1110 may be configured to propagate itsclock via synchronization packets to NTS node 1142, the timekeeper ofNTS network 1142. Note that each NTS network incorporates its ownmechanism of synchronizing clocks within each NTS network, thus, bysynchronizing the NTS timekeeper for an NTS network, the entire NTSnetwork may be synchronized with the TS network node. Thus, each NTSnode of NTS network 1130 may be synchronized with TS node 1120 and eachNTS node of NTS network 1140 may; be synchronized with TS node 1110.Therefore, all networks may be synchronized end-to-end.

FIG. 12: Flowchart for a Method for Synchronizing Clocks Between a TSand an NTS Network

FIG. 12 illustrates one embodiment of a method for a time-sensitive (TS)network interface controller (NIC) to synchronize a non-time-sensitive(NTS) network timekeeper. As described above, a TS network refers tonetworks adhering to the IEEE 802.1 standard for real-time data transferwhereas an NTS network refers to a real-time Ethernet networkimplementation such as PROFINET, which uses standards such as TCP/IP andEthernet along with a mechanism for real time and isochronous real timecommunication, EtherCAT, which is an open high performanceEthernet-based fieldbus system, Ethernet/IP, which is designed for usein process control and other industrial automation applications, orEthernet Powerlink, which is a deterministic real-time protocol forstandard Ethernet, among others. The method shown in FIG. 12 may be usedin conjunction with any of the systems or devices shown in any of theFigures described herein, among other devices. In various embodiments,some of the method elements shown may be performed concurrently, in adifferent order than shown, or may be omitted. Additional methodelements may also be performed as desired. As shown, this method mayoperate as follows.

In 1202 a clock of the TS NIC may be configured to synchronize to amaster clock, where the clock is coupled to a functional unit. The TSNIC may be similar to TS NIC 1000.

In 1204, a plurality of input/output queue pairs, coupled to thefunctional unit and a port, may be configured for segregation of VLANpackets based on VLAN tags, where each input/output queue paircorresponds to a respective NTS network. In some embodiments, theinput/output queue pairs may include pairs of NTS receive packet queuesand NTS transmit packet queues.

In 1206, the functional unit may be configured to, for each respectiveNTS network, generate synchronization packets usable by an NTS networktimekeeper of the respective NTS network to synchronize the NTS networkto the master clock. This may include using a TSU to generate timestamps for the synchronization packets in accordance with the clocksynchronized to the master clock.

In 1208, the functional unit may be configured to, for each respectiveNTS network, communicate with the respective NTS network via the portusing the corresponding input/output queue pair, including sending thesynchronization packets to the NTS network timekeeper of the respectiveNTS network.

In certain embodiments, the method may further include the functionalunit generating synchronization packets usable by an NTS networktimekeeper of the respective NTS network to synchronize the NTS networkto the master clock, including using the TSU to generate time stamps forthe synchronization packets in accordance with the clock synchronized tothe master clock. Additionally, the functional unit may communicate withthe respective NTS network via the port using the correspondinginput/output queue pair, including sending the synchronization packetsto the NTS network timekeeper of the respective NTS network.

In an exemplary embodiment, the functional unit may be furtherconfigured to egress the synchronization packets via the output queue ofthe at least one input/output queue pair based on a specified egressperiod, wherein the specified egress period specifies a time window andfrequency for egressing the synchronization packets. Further, the methodmay include the function unit egressing the synchronization packets viathe output queue of the at least one input/output queue pair based on aspecified egress period, wherein the specified egress period specifies atime window and frequency for egressing the synchronization packets.

FIGS. 13-15: Systems and Methods for Scheduled Data Egress from a TSNetwork Switch

The systems and methods described below may allow for the scheduledegress of data from a TS network switch, and allow the schedulingoverhead of a TS network node to be offloaded to a TS network switch.Thus, the TS network node may send a plurality of packets to the TSnetwork switch that need to be scheduled and the TS network switch mayschedule and send the packets at the scheduled time.

FIG. 13: Exemplary Block Diagram of a TS Network Switch Configured forScheduled Data Egress

FIG. 13 is an exemplary block diagram of a TS network switch configuredfor scheduled data egress according to one embodiment. As shown in FIG.13, a TS network switch, such as TS network switch 1300, may include afunctional unit, such as functional unit 1320. Additionally, the TSnetwork switch may include a plurality of ports, such as ports 1310a-1310 d, and each port may be coupled to the functional unit andassociated with a respective set of network addresses for TS packets.Each port may be further configured with a respective set of egressperiods, where each TS packet has a destination address and a type thatspecifies a respective egress period, where each egress period mayspecify a respective time window and frequency for egressing TS packetsto network nodes based on the type of the TS packets. Further, the TSnetwork switch may include a plurality of queues, coupled to theplurality of ports and the functional unit, such as queues 1321 a-1321 ncoupled to port 1310 a, queues 1322 a-1322 n coupled to port 1310 b,queues 1323 a-1323 n coupled to port 1310 c, and queues 1324 a-1324 ncoupled to port 1310 d. Also, each queue may be associated with arespective TS packet type and a respective port of the plurality ofports.

In certain embodiments, the functional unit may be configured to receiveone or more TS packets asynchronously from a network node via a firstport. Thus, for example, functional unit 1320 may receive one or more TSpackets asynchronously from a network node via port 1310 a. In someembodiments, the first port may be configured to couple to an NTS nodeof an NTS network. In other embodiments, the first port may beconfigured to couple to a TS network node of a TS network. Additionally,the functional unit may be configured to determine a second port, suchas port 1310 b for egressing at least one of the one or more TS packetsbased on the destination address of the at least one TS packet. In someembodiments, the second port may be configured to couple to an NTS nodeof an NTS network. In other embodiments, the second port may beconfigured to couple to a TS network node of a TS network. Further, thefunctional unit may be configured to determine an egress period foregressing the at least one TS packet based on the type of the at leastone TS packet. Also, the functional unit may be configured to determinethat the at least one TS packet cannot currently be egressed from thesecond port. In some embodiments, to determine that a respective timewindow for egress of the at least one TS packet is closed, thefunctional unit may be further configured to determine that there isalready a queued TS packet of the same type queued in the first queuefor egress from the second port or determine that the second port iscurrently egressing a TS packet.

In response to determining that the at least one TS packet cannotcurrently be egressed, the functional unit may queue the at least one TSpacket in a first queue of the plurality of queues based on therespective TS packet type and destination address, where the first queueis associated with the second port. For example, functional unit 1320may determine that port 1310 b cannot currently egress the at least oneTS packet and, in response, may queue the at least one TS packet inqueue 1322 b.

The functional unit may be additionally configured to egress the atleast one TS packet in the respective time window from the second port.Thus, for example, functional unit 1320 may egress the at least one TSpacket via port 1310 b in the respective time window for port 1310 b. Insome embodiments, the at least one TS packet may include two or more TSpackets. In such embodiments, the respective time window of thedetermine egress period may be specified to allow the egress of one ofthe two or more TS packets. In certain embodiments where the at leastone TS packet may include two or more TS packets, specifying therespective time window of the determined egress may include determininga quantity of the two or more TS packets to egress each egress periodand configuring the respective time window to allow the egress of thequantity each egress period. In some embodiments, where two or moreports of the TS network switch may be configured to couple to respectiveNTS networks, TS packets for each of the two or ports may be scheduledto egress concurrently, thus allowing two or more NTS networks toreceive TS packets concurrently.

FIG. 14: Illustration of a Time-Based Scheduled Egress from a TS NetworkSwitch

FIG. 14 is an illustration of an exemplary schedule for a time-baseddata egress from a TS network switch, such as TS network switch 1300. Attime A, TS packets 1-4 may be asynchronously ingressed to the TS networkswitch and queued as described above. For simplification, it is assumedthat all TS packets egressed at time A are of the same packet type andsame destination address. Additionally, for simplicity, it is assumedthat the egress period is specified such that a single TS packetegresses each egress period. Then, at time B, TS packet 1 is dequeuedand egressed. During the egress of TS packet 1, the “window of time” is“open” allowing the TS packet to be egressed. Then, after a specifiedduration, the “window of time” is “closed” and the TS switch waits forthe next egress period to begin. At time C, TS packet 2 is dequeued andegressed. Similarly, at times D and E, TS packets 3 and 4, respectively,are dequeued and egressed. In such a manner, TS packets receivedasynchronously at the TS network may be egressed on a time-basedschedule.

FIG. 15: Flowchart of a Method for Scheduled Data Egress from a TSNetwork Switch

FIG. 15 illustrates a method for scheduled data egress from a TS networkswitch, according to one embodiment. The method shown in FIG. 15 may beused in conjunction with any of the systems or devices shown in any ofthe Figures described herein, among other devices. In variousembodiments, some of the method elements shown may be performedconcurrently, in a different order than shown, or may be omitted.Additional method elements may also be performed as desired. As shown,this method may operate as follows.

In 1502, a TS network switch may be provided. The TS network switch mayinclude a functional unit, a plurality of ports, and a plurality ofqueues. The plurality of ports may be coupled to the functional unit andmay be associated with a respective set of network addresses for TSpackets. Additionally, each port may be configured with a respective setof egress periods and each TS packet may have a destination address anda type that may specify a respective egress period. Further, each egressperiod may specify a respective time window and frequency for egressingTS packets to network nodes based on the type of the TS packets. Also,the plurality of queues may be coupled to the plurality of ports and thefunctional unit and may be associated with a respective TS packet typeand a respective port of the plurality of ports.

In 1504, the functional unit may be configured to receive one or more TSpackets asynchronously from a network node via a first port. In someembodiments, the first port may be configured to couple to an NTS nodeof an NTS network. In other embodiments, the first port may beconfigured to couple to a TS network node of a TS network.

In 1506, the functional unit may be configured to determine a secondport of the plurality of ports for egressing at least one of the one ormore the TS packets based on the destination address of the at least oneTS packet. In some embodiments, the second port may be configured tocouple to an NTS node an NTS network. In other embodiments, the secondport may be configured to couple to a TS network node of a TS network.

In 1508, the functional unit may be configured to determine an egressperiod for egressing the at least one TS packet based on the type of theat least one TS packet. In some embodiments, the at least one TS packetmay include two or more TS packets. In such embodiments, the respectivetime window of the determined egress period may be specified to allowthe egress of one of the two or more TS packets. Alternatively, in othersuch embodiments, to specifying the respective time window of thedetermined egress may include determining a quantity of the two or moreTS packets to egress each egress period and configuring the respectivetime window to allow the egress of the quantity each egress period.

In 1510, the functional unit may be configured to determine that the atleast one TS packet cannot currently be egressed from the second port.In some embodiments, to determine that the at least one TS packet cannotcurrently be egressed, the functional unit may be further configured todetermine that a respective time window for egress of the at least oneTS packet is closed, determine that there is already a queued TS packetof the same type queued in the first queue for egress from the secondport, or determine that the second port is currently egressing a TSpacket.

In 1512, the functional unit may be configured to queue the at least oneTS packet in a first queue of the plurality of queues based on therespective TS packet type and destination address in response todetermining that the at least one TS packet cannot currently beegressed, wherein the first queue is associated with the second port.

In 1514, the functional unit may be configured to egress the at leastone TS packet in the respective time window from the second port.

In further embodiments of the method, the functional unit may receiveone or more TS packets asynchronously from a network node via a firstport and determine a second port of the plurality of ports for egressingat least one of the one or more the TS packets based on the destinationaddress of the at least one TS packet. Additionally, the functional unitmay determine an egress period for egressing the at least one TS packetbased on the type of the at least one TS packet and determine that theat least one TS packet cannot currently be egressed from the secondport. Also, the functional unit may queue the at least one TS packet ina first queue of the plurality of queues based on the respective TSpacket type and destination address in response to determining that theat least one TS packet cannot currently be egressed, where the firstqueue is associated with the second port. Accordingly, the at least oneTS packet may be egressed in the respective time window from the secondport.

In certain embodiments of the method, the functional unit, in order todetermine that the at least one TS packet cannot currently be egressed,may determine that a respective time window for egress of the at leastone TS packet is closed, determine that there is already a queued TSpacket of the same type queued in the first queue for egress from thesecond port, or determine that the second port is currently egressing aTS packet.

In other embodiments of the method, the TS packet may include two ormore TS packets. In such embodiments, the respective time window of thedetermined egress period may be specified to allow the egress of one ofthe two or more TS packets. Alternatively, specifying the respectivetime window of the determined egress may include the functional unitdetermining a quantity of the two or more TS packets to egress eachegress period and configuring the respective time window to allow theegress of the quantity each egress period.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations and modifications.

We claim:
 1. A method for scheduled data egress, comprising: providing atime-sensitive (TS) network switch, wherein the TS network switchcomprises: a functional unit; a plurality of ports coupled to thefunctional unit, wherein each port is associated with a respective setof network addresses for TS packets, wherein each port is configuredwith a respective set of egress periods, wherein each TS packet has adestination address and a type that specifies a respective egressperiod, wherein each egress period specifies a respective time windowand frequency for egressing TS packets to network nodes based on thetype of the TS packets; and a plurality of queues, coupled to theplurality of ports and the functional unit, wherein each queue isassociated with a respective TS packet type and a respective port of theplurality of ports; and configuring the functional unit to: receive oneor more TS packets asynchronously from a network node via a first port;determine a second port of the plurality of ports for egressing at leastone of the one or more the TS packets based on the destination addressof the at least one TS packet; determine an egress period for egressingthe at least one TS packet based on the type of the at least one TSpacket; determine that the at least one TS packet cannot currently beegressed from the second port; queue the at least one TS packet in afirst queue of the plurality of queues based on the respective TS packettype and destination address in response to determining that the atleast one TS packet cannot currently be egressed, wherein the firstqueue is associated with the second port; and egress the at least one TSpacket in the respective time window from the second port.
 2. The methodof claim 1, further comprising: the functional unit performing:receiving one or more TS packets asynchronously from a network node viaa first port; determining a second port of the plurality of ports foregressing at least one of the one or more the TS packets based on thedestination address of the at least one TS packet; determining an egressperiod for egressing the at least one TS packet based on the type of theat least one TS packet; determining that the at least one TS packetcannot currently be egressed from the second port; queuing the at leastone TS packet in a first queue of the plurality of queues based on therespective TS packet type and destination address in response todetermining that the at least one TS packet cannot currently beegressed, wherein the first queue is associated with the second port;and egressing the at least one TS packet in the respective time windowfrom the second port.
 3. The method of claim 1, wherein to determinethat the at least one TS packet cannot currently be egressed from thesecond port, the functional unit is configured to: determine that arespective time window for egress of the at least one TS packet isclosed; determine that there is already a queued TS packet of the sametype queued in the first queue for egress from the second port; ordetermine that the second port is currently egressing a TS packet. 4.The method of claim 3, further comprising: the functional unitperforming: receiving one or more TS packets asynchronously from anetwork node via a first port; determining a second port of theplurality of ports for egressing at least one of the one or more the TSpackets based on the destination address of the at least one TS packet;determining an egress period for egressing the at least one TS packetbased on the type of the at least one TS packet; determining that the atleast one TS packet cannot currently be egressed from the second port,wherein said determining comprises: determining that a respective timewindow for egress of the at least one TS packet is closed; determiningthat there is already a queued TS packet of the same type queued in thefirst queue for egress from the second port; or determining that thesecond port is currently egressing a TS packet; queuing the at least oneTS packet in a first queue of the plurality of queues based on therespective TS packet type and destination address in response todetermining that the at least one TS packet cannot currently beegressed, wherein the first queue is associated with the second port;and egressing the at least one TS packet in the respective time windowfrom the second port.
 5. The method of claim 1, wherein the at least oneTS packet comprises two or more TS packets.
 6. The method of claim 5,wherein the respective time window of the determined egress period isspecified to allow the egress of one of the two or more TS packets. 7.The method of claim 5, wherein specifying the respective time window ofthe determined egress comprises: determining a quantity of the two ormore TS packets to egress each egress period; and configuring therespective time window to allow the egress of the quantity each egressperiod.
 8. The method of claim 1, wherein the first port is configuredto: couple to a non-time-sensitive (NTS) node of an NTS network.
 9. Themethod of claim 8, wherein the second port is configured to: couple toan NTS node of another NTS network.
 10. The method of claim 1, whereinthe first port is configured to: couple to a TS network node of a TSnetwork.
 11. The method of claim 10, wherein the second port isconfigured to: couple to a non-time-sensitive (NTS) node of an NTSnetwork.
 12. A time-sensitive (TS) network switch for scheduled dataegress, comprising: a functional unit; a plurality of ports coupled tothe functional unit, wherein each port is associated with a respectiveset of network addresses for TS packets, wherein each port is configuredwith a respective set of egress periods, wherein each TS packet has adestination address and a type that specifies a respective egressperiod, wherein each egress period specifies a respective time windowand frequency for egressing TS packets to network nodes based on thetype of the TS packets; and a plurality of queues, coupled to theplurality of ports and the functional unit, wherein each queue isassociated with a respective TS packet type and a respective port of theplurality of ports; wherein the functional unit is configured to:receive one or more TS packets asynchronously from a network node via afirst port; determine a second port of the plurality of ports foregressing at least one of the one or more the TS packets based on thedestination address of the at least one TS packet; determine an egressperiod for egressing the at least one TS packet based on the type of theat least one TS packet; determine that the at least one TS packet cannotcurrently be egressed from the second port; queue the at least one TSpacket in a first queue of the plurality of queues based on therespective TS packet type and destination address in response todetermining that the at least one TS packet cannot currently beegressed, wherein the first queue is associated with the second port;and egress the at least one TS packet in the respective time window fromthe second port.
 13. The TS network switch of claim 12, wherein todetermine that the at least one TS packet cannot currently be egressedfrom the second port, the functional unit is configured to: determinethat a respective time window for egress of the at least one TS packetis closed; determine that there is already a queued TS packet of thesame type queued in the first queue for egress from the second port; ordetermine that the second port is currently egressing a TS packet. 14.The TS network switch of claim 12, wherein the at least one TS packetcomprises two or more TS packets.
 15. The TS network switch of claim 14,wherein the respective time window of the determined egress period isspecified to allow the egress of one of the two or more TS packets. 16.The TS network switch of claim 14, wherein specifying the respectivetime window of the determined egress comprises: determining a quantityof the two or more TS packets to egress each egress period; andconfiguring the respective time window to allow the egress of thequantity each egress period.
 17. The TS network switch of claim 12,wherein the first port is configured to: couple to a non-time-sensitive(NTS) node of an NTS network.
 18. The TS network switch of claim 17,wherein the second port is configured to: couple to an NTS node ofanother NTS network.
 19. The TS network switch of claim 14, wherein thefirst port is configured to: couple to a TS network node of a TSnetwork.
 20. The TS network switch of claim 19, wherein the second portis configured to: couple to a non-time-sensitive (NTS) node of an NTSnetwork.